1. Field of the Invention
This invention relates generally to placer mining equipment and more particularly to an apparatus including a suction nozzle for extracting and a moving an ore bearing slurry to an ore separating device and selectively operable puddling nozzle for directing slurry producing water to an otherwise dry area to be mined.
2. Description of the Prior Art
As is known, placer mining is a technique used for extracting ores, such as gold, from river beds and other water bodies. A slurry mixture of water and ore bearing soil is extracted from the river bed and placed in a ore separating apparatus, such as a sluice box. The sluice box is operated to separate the ore from the soil and water.
In relatively sophisticated placer mining operations, a high pressure water pump extracts water from the river bed and directs it to a suction nozzle which extracts the ore bearing soil in slurry form from the river bed and delivers it to the sluice box.
One indispensable commodity needed for placer mining operations is water, without it, placer type mining operations are impossible. In sites where river beds have changed course, are of reduced width, or have dried up completely, many desirable mining sites are left unmined due to the lack of water.
One way of overcoming the problem of a lack of water at a mining site where it is desirable to utilize placer mining techniques is, of course, to transport water to the site and dump it into the area to be mined. This is impractical due to the tendency for water to spread out and rapidly sink into the dry ground. In that the water must be transported to the mining site, it is imperative that the water be conserved and used as efficiently as possible. To the best of my knowledge, no mechanism or technique has been devised or suggested which accomplishes the objectives of water conservation and efficient use of the water transported to dry mining sites for use in accomplishing placer type mining.
I am however, aware of a hydraulic conveyer apparatus which is disclosed in U.S. Pat. No. 1,518,528, which issued to H. T. Libby on Dec. 9, 1924. The Libby apparatus includes a water supply line which directs water under pressure from a remote source to a T-junction having a pair of hand-operated valves each at a different one of the outlets of the T-junction. A first elongated hose is coupled to one of the T-junction outlets and a washing nozzle is mounted on the distal end of that first hose for driving dirt and rocks into a previously dug hole and subsequently enlarging the hole to uncover a subterranean hard rock layer that is to be quarried. A second hose is coupled to the other outlet of the T-junction and has a conventional hose nozzle on its distal end which is mounted by a special screen structure so that the nozzle is axially disposed in the intake end of a waste material conveyer pipe to provide a suction at the inlet of the pipe. The hose nozzle, screen structure and intake end of the conveyer pipe are disposed in the previously dug hole, and operate to carry away the driven dirt and rocks along with the water from the washing nozzle. While the apparatus of the Libby patent could be used for placer mining, it has several drawbacks which make it unsuited and impractical for such use. The first drawback of the Libby structure must be of a relatively high volume and pressure in order to accomplish the objective of driving the dirt and rocks, and such volume and pressure are considerably greater than is needed for placer mining. Further, since the water emitted from the washing nozzle is at a variable distance from the intake end of the conveyer pipe, the water will tend to sink into the ground and be lost. This is not a problem with the Libby apparatus in that it is operating on a quarry bed which has little or no porosity. However, this is usually not the case in placer mining sites. The second drawback of the Libby structure is related to its lack of mobility as is needed, or at least highly desirable in placer mining. Placer mining is usually accomplished by one person who carries a suction nozzle from one place to another at the mining site, and this requires the use of an easily handled portable suction nozzle which can, in addition to its material carrying capabilities, be used to burrow into the ground. The Libby apparatus is totally unsuitable for this type of use in that it cannot be easily carried by one person from place to place and operated while being held by that person. Further, the suction end of the materials conveyer pipe of the Libby apparatus is obstructed by the hose nozzle and screen structure and thus cannot be used to accomplish burrowing operations as needed in placer mining, but must, instead by used in a pre-existing depression or hole dug for that purpose.
Another problem with the Libby apparatus is that because the elevation of the discharge end of the waste conveyer pipe with respect to its intake end will vary depending on the depth of the depression, it is necessary to control the pressure of the water delivered to the injector nozzle; i.e. for a deep depression, the pressure must be increased, and for a shallow depression, it should be decreased. Thus, the Libby apparatus is provided with two separate flow control valves: one for controlling the flow of water to the washing nozzle mechanism, and one for controlling the flow of water to the injection nozzle. The two valve structure is expensive to manufacture, and does not allow for convenient one handed operation.
Therefore, a need exists for a new and useful placer mining suction nozzle having a puddling means which allows the use of placer mining techniques in dry areas and which overcomes some of the difficulties and shortcomings of the prior art.